PepsiCo.-Starbucks Connection

To whom it my concern:
We own stock in Starbucks Corp. and have just found out that Starbucks and
PepsiCo. are in a joint venture together. How do you recommend that we
tell Starbucks of our dismay? i.e. Do you have the address or e-mail
address or Starbucks so that we my write them?
Thank you for your time we look forward to your reply.
Sincerely,
Bill Turner
Emily Turner